I have the AJ16 engine. I can never keep the camcover gasket from leaking for long. I follow torque values, tightening sequences, etc.

The one thing I've noticed is that some of the bolt gaskets, NBC2575CA get squished as I torque the bolts down (with the metal washer) to the required 6.5Nm.

I've used OEM Jaguar gaskets and bolt gaskets, as well as aftermarket, and no significant difference. What the hell am I doing wrong?

 

Have you inspected the surfaces of the cover? the slightest distortion will cause it to nip the gaskets and move them around when you fasten them down. Had the same issue with my XJR, although the cover looked spot on, when I tried a new one the problem never came back

 

You are doing nothing wrong.

My X300 (4 door version of the late XJS) with the 3.2ltr engine had that when it arrived. Marking it territory something savagely.

I did it 4 times, and too many beers, and still not happy, and $$ gone forever.

I looke at the shanked bolts, meaning they are a fixed length "crush" on the gaskets/seals. No matter how tight you do those bolts, they will never pull the cover tighter, it is what it is.

More$$, OE gasket, bolts seals "out of stock", fair dinkum.

Anyway, looking at these bolts, and then the penny dropped, I found in my endless stash of Jag stuff, a box of 1/32" fibre washers, whoopee.

Placed a washer under the head of the bolts, and thus increased the "crush" by 1/32" all round.

BUT

Still not convinced.
Looked at the PCV filter thingy in the cover, oh dear, what a mess. 4 hours later, and heaps of solvent through the spigot, and compressed air blasted into that spigot, I had acceptable air flow. I summised that the engine could NOT breath, and the weakest point was the exit for the pressure and took oil with it.

A sweet smear of Hi-Temp Grey RTV, paying attention to the D Seals, fitted the cover, and tightened "just firm". Did the final tighten to the shank step next morning. I never used the spec torque, they are SMALL bolts, and the threaded section is too easily snapped off, so good old Aussie Common Sense fixes all.

10 years on, NO BLOODY LEAKS.

Was it the washers?, RTV?, cleaning the breather?, dunno, care factor pretty low, it dont leak, who cares.

Beer O'clock.